Hi there, this is really urgent. Some of our clients make calls and can't hear the AI assistant speaking. For example call ID 51e172bb-5c64-4b09-9006-ea0a04bb2ffb As you can hear, in the recording we can hear both the AI and the human caller, but the human caller can't hear the AI. It happened with different calls, from different callers. Note that it works often fine, it seems a bit random. Note that vapi categorizes the call as "outbound call" but it's more an inbound call. The reason is that our twilio webhook points to a custom

/twilio/inbound-call

on our server , which calls the

/call

endpoint of vapi, like that:

response = await client.post(
                "https://api.vapi.ai/call",
                json={
                    "phoneNumber": {
                        "twilioAccountSid": "XXX",
                        "twilioAuthToken": s"XXX",
                        "twilioPhoneNumber": "XXX",
                    },
                    "phoneCallProviderBypassEnabled": True,
                    "customer": {"number": recipient_number},
                    "assistant": assistant_config,
                    "assistantOverrides": {
                        "server": {
                            "url": f"{api_url}/vapi-messages",
                            "secret": secrets.vapi_secret,
                        }
                    },
                },
                headers={
                    "Content-Type": "application/json",
                    "Accept": "application/json",
                    "Authorization": f"Bearer {secrets.vapi_api_key}",
                },
                timeout=10.0,
            )

Also, I've noticed that, despite not specifying it in

vapi_server_events

, our endpoint

f"/vapi-messages"

gets a strange

phone-call-control

that I ignore. And I am not sure what

phoneCallProviderBypassEnabled

does, but it seems required to make it work. Thank you for your help!

message has been deleted

it's not relevant, I'd like a human to troubleshoot please.

Same issue for us! Started happening around 1 hour ago.

For us, we started noticing it yesterday (but not sure when it exactly started as it often works fine).

Had this happen to me the other day.

Your problem seems different from mine. The assistant can’t be heard by the caller for me (but when you play the recording, you can hear it and it works as expected, ie reacting to caller’s speech even though caller can’t hear)

@AdeB @Kachinni @btbrtv @AdeB Apologies for the delay. I'm checking if this issue has been resolved for you. If not, please share the recent call IDs so I could take a look.

c15126b9-e3aa-48d3-8c74-2914122493b8 7b87c91e-c311-4a57-aa36-cf1e5aa00015 9ca9e9d9-999b-474b-bb37-b2ec25907d73 8ade4040-875d-486c-a1a0-55352637bb7e All the same issue

Thank you @Shubham Bajaj for your answer! for example call ID 51e172bb-5c64-4b09-9006-ea0a04bb2ffb we are still having issues. > phone-call-control is used to manage and control how phone calls are transferred - ideally you don't need it as Vapi handles this for you. Ok! It is still sent to my vapi endpoint, despite not being specified in the assistant server messages. I simply ignore it. (and thank you for the info on the inner workings!)

@AdeB can you help me with the follwowing info about your issue, I'm littel confused here. - What response you expected to get - What response you actually got instead

> What response you expected to get I was expecting the caller to hear the assistant > What response you actually got instead Caller couldn't hear the assistant, even though the recording file in vapi has both the caller and assistant recorded. We could reproduce the issue with different callers, so it's not tied to a particular caller.

@AdeB The assistant can clearly hear the user and respond to it on the user's side. There are two possibilities: either it's because of endpointing or something is wrong on the user's side. It appears to be related to endpointing - try setting the Deepgram endpointing to 300ms, waitSeconds to 800 milliseconds, and smartEndpointing to true since it's English transcription (our own trained model to detect user has finished speaking). Try it without the transcriptionEndpointingPlan first and let me know how it goes.

Thank you @Shubham Bajaj, making the changes and will report soon

@AdeB yeah man the endpointing depends upon the call nature and call environment.

Thank you for checking in Shubahm, it’s not solved yet. It’s a bit hard to make your suggested changes but it’s planned. Count on me to give an update here

@AdeB FYI: ticket will be opened for next 2 days, If I didn't received a reply I have to close the ticket.

@Shubham Bajaj FYI we found the culprit: WIFI calling. If the caller deactivates it, it works as expected. If not, we get the issue. Also note that we are using call forwarding (recipient's number is forwarded to the twilio number that we control). Have you encountered this issue before?

@AdeB I'm assuming by recipient's number you mean personal mobile number and it's hard to tell what's wrong, could you share the following in a new #1211483291191083018 ticket: - The call ID - When exactly this happened (the timestamp) - What response you expected to get - What response you actually got instead This would really help me figure out what went wrong!